The RMA (RMO is a misnomer) is a concept specific to ppc64 (in fact
server ppc64 though I hijack it on embedded ppc64 for similar purposes)
and represents the area of memory that can be accessed in real mode
(aka with MMU off), or on embedded, from the exception vectors (which
is bolted in the TLB) which pretty much boils down to the same thing.
We take that out of the generic MEMBLOCK data structure and move it into
arch/powerpc where it belongs, renaming it to "RMA" while at it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds the base support for the 476 processor. The code was
primarily written by Ben Herrenschmidt and Torez Smith, but I've been
maintaining it for a while.
The goal is to have a single binary that will run on 44x and 47x, but
we still have some details to work out. The biggest is that the L1 cache
line size differs on the two platforms, but it's currently a compile-time
option.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Today's linux-next build (powerpc ppc44x_defconfig) failed like this:
arch/powerpc/mm/pgtable_32.c: In function 'mapin_ram':
arch/powerpc/mm/pgtable_32.c:318: error: too many arguments to function 'mmu_mapin_ram'
Casued by commit de32400dd2 ("wii: use both
mem1 and mem2 as ram").
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This is some preliminary work to improve TLB management on SW loaded
TLB powerpc platforms. This introduce support for non-atomic PTE
operations in pgtable-ppc32.h and removes write back to the PTE from
the TLB miss handlers. In addition, the DSI interrupt code no longer
tries to fixup write permission, this is left to generic code, and
_PAGE_HWWRITE is gone.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
total_lowmem represents the amount of low memory, not the physical
address that low memory ends at. If the start of memory is at 0 it
happens that total_lowmem can be used as both the size and the address
that lowmem ends at (or more specifically one byte beyond the end).
To make the code a bit more clear and deal with the case when the start of
memory isn't at physical 0, we introduce lowmem_end_addr that represents
one byte beyond the last physical address in the lowmem region.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 44x family has an interesting "feature" which is a virtually
tagged instruction cache (yuck !). So far, we haven't dealt with
it properly, which means we've been mostly lucky or people didn't
report the problems, unless people have been running custom patches
in their distro...
This is an attempt at fixing it properly. I chose to do it by
setting a global flag whenever we change a PTE that was previously
marked executable, and flush the entire instruction cache upon
return to user space when that happens.
This is a bit heavy handed, but it's hard to do more fine grained
flushes as the icbi instruction, on those processor, for some very
strange reasons (since the cache is virtually mapped) still requires
a valid TLB entry for reading in the target address space, which
isn't something I want to deal with.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
APUS (the Amiga Power-Up System) is not supported under arch/powerpc
and it's unlikely it ever will be. Therefore, this patch removes the
fragments of APUS support code from arch/powerpc which have been
copied from arch/ppc.
A few APUS references are left in asm-powerpc in .h files which are
still used from arch/ppc.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch takes the definitions for the PPC44x MMU (a software loaded
TLB) from asm-ppc/mmu.h, cleans them up of things no longer necessary
in arch/powerpc and puts them in a new asm-powerpc/mmu_44x.h file. It
also substantially simplifies arch/powerpc/mm/44x_mmu.c and makes a
couple of small fixes necessary for the 44x MMU code to build and work
properly in arch/powerpc.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The PIN_SIZE definition name changed, update 44x_mmu.c accordingly.
Signed-off-by: Matt Porter <mporter@embeddedalley.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This creates the directory structure under arch/powerpc and a bunch
of Kconfig files. It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.
For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes
to files in those directories and files outside arch/powerpc.
The boot directory is still not merged. That's going to be interesting.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Benjamin Herrenschmidt